Fuse block



6, 1943- J. B. GRIFFF'TH 2,334, 5 50 FUSE BLOCK Filed Aug. 14, 1942 4 NVENTQR.

Patented Nov. 16, 1943 f This invention relates generally to fuse'blocks and more particularly to the open or exposed type block for a cartridge fusewith terminals for properly connecting it in an electric circuit and the method of making the electrical connec tion therewith. 1

I. The principal object. of this invention is. the

method and apparatus for obtaining aligned pos-' itive pressure connections on the ends of a cartridge type .fuse'. V

Another object is the provision of a fuse block V thatis readily accessible for the replacement of a cartridge fuse.

r nother object the provision of ia cartridge fuseblock provided with self-aligning terminals which engage and exert positive pressure upon the ends of the fuse. e

Another object is. they provisionjof cartridge fuse block terminals thatproduce positive prese sure againstthe fuse ends and which maybe locked against movement to prevent displacement accidentally or by vibration. f Another object is the provision of a cartridge type fuse. block having rod posts arranged to be Connected to the electric circuit. Q' Another object is the method of securing the fuse terminal blocks to apanel board (orthe 1i ke' l l Other objects and advantagesappear in f ollo'wing' description and claims.

,In the accompanying drawing "practical enibodiments illustrating the principles of this invention are shown wherein Fig. 1v is anperspective viewof an improved terminalblock having a cartridge fuseinounted Q Fig. Zfisa vertical sectional View of t em blockshow'n in Fig. 1. V i V V Fi 3 is a'perspective view of a terminal block 1 illustrating another. form of'mountingi Fig. 4 isa horizontal sectional view through a terminaliblock illustrating another form. of invention.'

a Referring parties-as to Figs. 1 and' 2 t e cartridgetype fuse block illustrated therein is J niade up ofthr'ee principal partsfthe base I lland two terminal blocks l and 12 which are mounted in alignment onthe ease; Thebase [Umaybe formdlintegralzwith the blocks II and [2, but in some installations it is preferred to have the blocklof insulating material and a metal base "asshowniin Figs. 1 and 2 If thefuse blocksare n ade up to receive a" single cartridge iuse the ,metalbase '10 is provided with some means, such as the holes I3 at each endthereoi, for panel v switchboard or panel l0 withsufiicient clearance i a switchboard ior rconnection with parallel-;cir-.

The dovetail of eachv'block isindented intermediateyof its ends and .Ithetmetall' of orboar'd mounting. However a steelfbox or largepanelinay beused as thebaselllwith the terminal blocks suitab'ly positionedthereonffor g supplying the desired circuitarrangements In Figs. ra d-2 the-terminal blocks [and I2 are'shown fastened to'tliemetalbase lfl'by' the tongues 14 struck from the If the cartridge fuse l5 is'short, therebyplacing the terminal blocks. II andi2 relatively close togetherfthe' tongues l4' m'a'yflhave to be staggered as-illus- 'trated in FigL Z of the drawing. able'means may be employed for securing the terminal blocks to' the base-such as set screws, rivets'orthelike.- E i A large panel onswitchboard base having two sets of opposed' fiarige's I6; as shown'in Fig1 3,f may'be used for securing dovetailed portions of the-terminal blocks- I hand l2; The opposed parallel flanges 16in ea'ch set'rii'ay belspot -weldled or otherwise secured tothesurface of'the adjacentthe end ofeachset to permit the'dove- "tailed-or grooved base of the blocks, l land 12 to. -be"inse1ted*urider the flanges and slid :the'realong until they are properly aligned with each other and with the circuit: to be connected :theretmThis .providesFa very'goodimethod for securing a series .of terminal blocks rows-"on cults.

the-flange l6,is,.crimped intothis indentationas "showniat H to secure the. block in position; The

thickness of'thefterminal.blocksdetermines the .4 proper spacingfor acompact series of; fuses but they may be securediin spaced relation if there adequate room ton the panel. The novel 1 method ;of;building up a panel board-or switch box hasmany advantages; The circuits may be set up inany desired manner and they may be.

changedaoradded' to without destroying or remetal angl brackets (s and I 9. The; or zontal n e of a h ee g'b e 1s fi d i s 'with Any 'othersuit hole for receiving the rivet 29 which hole is larger than the rivet that loosely holds the angle bracket in the pockets between the upstanding walls 2| of the terminal blocks. The walls 2| are spaced apart sufficiently to permit the brackets to pivot through a small are on each side of the axial center of the blocks.

The bracket [8 has an opening 22 in itsupe wardly extending leg to receive the stem 23 of the disk terminal member 24. The hole 22 is larger in diameter than the stem 23 topermit the latter to float therein.

The bore of the sleeve 26 carries the stem 23 of the other terminal member 24 andis also suffi ciently large in diameter to permit the terminal member to float therein. The outer end of the and is provided with an enlarged axial opening for receiving the sleeve 26. An upwardly open recess 35 is provided in the bridge 3| and is shaped to receive the nut 36 and prevent it from turning. The nut 36 is dropped in the recess and the sleeve 26 is inserted in the hole 34 and threaded through the nut. A second nut 31 may be placed on the threaded sleeve and jammed against the face of the bridge 3| to lock the sleeve against accidental movement.

The integral "block shown in fig. 4 may be mounted in either method previously described.

The bracket I9 is provided with a threaded hol e -"Ihis block may be provided with a dovetailed 25 for receiving the externally threaded sleeve; 2 fi. ,g rbasealons the S des 0 On the e thereof,

pending which is most suitable for the installation;

- Thus the cartridge fuse may be securely connected in'an electrical circuit by a high positive sleeve 26 has a disk 21 secured thereto wiiloh when turned between the thumb ,and finger clamped bet een t e two. er i l m e a Any misalignmentdue to the mounting, of the ,terminalblocks or the end ,ferrules of the cartridge fuse is .readily' compensated by he selfaligning pivoting-action of the brackets and the floating action of the terminalmembera; thereby providing fiat engagement with the fuse ends. The heads ;of the-terminal ,members being flat ;-p rmi;t s :them to p per y en a e theends :0f .the cartri e fusesnd eliminatesthe d ffi ultiesof .capped' termmals. If. the thread .on -,th,e.-s-1eeve:is provided with .a small pitch themechanical advantage of thejforce ion the :terminal members .may be increased. .,-High contact pressurezhetween. .the terminals and athe ifuse ;member. proslides :lowzresistance .electrical contact, thereby improvingdhaefliciency :of the .fuse and the cir- 101111; :connettedithereto. J

Thesterrm'nal members being made upzofrazheed with .an integral stem extending axially 'ztherestrum .provide an ideal means for-soldering or electrically .connectingwawire thereto by means of'asleeve connector. This connection canbe k :made :wholly within the :walls 21 of the block, thereby providingadditional protection'to those who i are changing or ;otherwise required to work .on {the switch board while it 'is energized;

The structure shown -'in -Fig. 4 illustrates a unitary fuse block wherein the'block's l=l and 12 are molded. or pressed from a plastic or-other similar insulating -material.. T The brackets ane replaced by the bri'dges 3 0 and 8 I whichare disposed transversely-of the fuse 1 block and connect the upwardly extending walls 21; The h'o'le'32 in the br idge .30 takes the-placeof :the hole '22 in the bracket 48, and -the*-inner face -of the bridge is provided with -'a socketarranged to receive the spherical surface 831m the back of the headof pressure axially of the fuse which does not depend-upon the flexing characteristics of aleaf or can spring. This high 'conta'ct -pressure -re- I duces ,the resistance of the circuit, thereby in creasing the efllciency offith'e fuse. "The high positive pressureis axially of the tubular cartridge fuse which is the dimension of its greatest strength. Again the fuse may be readily locked against accidental displacement due to vibration. These are particular advantages-attainable by means of this improved structure and method .cf connecting a.cartridge fuse in .an electric circuit.

I claim:

1. 'In a fuse block; the combination of a pair of terminal blocks of insulatingmaterial dis- .posedlin spaced 'r'elation'jand thaving upwardly and ,outwardly opposed pockets arranged to receive the-"end portions of the fuse, supporting means in each pocket, a terminal member of conductive material 'carriedby' each of said suporting means andarranged .to con'cluctively engage the end surfaces of the fuse, and means for actuating one "of said supporting 'means'to move at least one of said .terminal members *toward and'away from .the other terminal member to clamp the fuse fixedly between them or to the terminal member- 24: Thus'fithe terminal release the fuse forremoval. 7

12. In 1a fuse block; the "combination of a pair of terminaihbloc'ks of "insulating-material disposed in spaced relation and having upwardly and outwardly "opposed pOCkEtS arranged 'to receive. the end portions of the-fuse, supporting means :in each po cket, a :terminal member of conductive material carried'by'each of said'supporting means and arranged to conductively engage ith'e end surfaces of the fuse,.said terminal'memhers-being loosely held to compensate for misalignment, and means for actuating one ofsaid supporting means to move at least oneof said terminal members toward and away 'fromthe other terminal member to clamp the fuse fixedly between them or to release theffuse for removal.

3. in a fuse block, "the-combination 10f a pair of opposed pockets of insulating 'material";dis-

posed in spaced relation and arranged to receive the 'fiildjPOIiiiOl'lS: of the fuse. sai'd pockets having transverse/walls provitledwith' aligned holes a pair of fconductive terminal members '"heads' arrangedfto engage the endsurfaces of the-fuse andfaljsoprovidcd with axial'stlems extending 'rearwardly throughthe :holes, amit in one of -said pockets held 'againstfl otation, fan exteriorly threaded sleeve threadedly engaging the nut and extending through the hole in the her and surrounding *thestem thereof; and-means associated terminal member to move either toward or away from the other terminal member to either clamp the fuse fixedly between the terminal members or to release the fuse for removal. 4. In a fuse block, the combination of a pair of opposed pockets of insulating material disposed in spaced relation and arrangedto receive the end portions of. the fuse, said pockets having transverse walls provided with aligned holes, a

,pair of conductive terminal members having heads arranged to'engage the end surfaces of the fuse andalso provided with axial stems extending rearwardly through the holes, a nut in one of said pockets held against rotation, an exteriorly threaded sleeve threadedly engaging the nut and extending through the hole in the associated Wall, said sleeve arranged .to abut against the head of the associated terminal member and surrounding the stem thereof, means for rotating the sleeve in the nut to cause the associated terminal member to move either toward or away from the other terminal member to either clamp the fuse fixedly between the terminal members or to release the fuse for removal, and means for preventing accidental rotation of the sleeve to lock the fuse in place. a

5. In a fuse block, the combination of a base of suitable material, a pair of upwardly and outwardly opposed pockets of insulatingmaterial detachably mounted on the baseandarranged to receive the end portions of the fuse, a ter minal support in each of said pockets, a sleeve arranged for axial movementin one of said supports, terminal members of conductive material having heads arranged to have fiat surface engagement with the ends of the fuse, one terminal member carried by the sleeve and the other by the opposed terminal support, and means for actuating the sleeve to move the associated terminal member either toward or away from the other terminal member to clamp the fuse fixedly in place-or to release the fuse for removal.

6. In afuse block, the combination of a base of suitable material, a pair of terminal blocks of insulating material having opposed pockets,

said terminal blocks mounted on the base and arranged for slidable movement thereon, means for retaining the terminal blocks with the pockets in aligned selected positions on the base, terminal members of conductive material carried by the pockets and having heads arrangedto have flat surface engagement with the ends of the fuse, and means for movingone of the terminal members either toward or away from: the other terminal member-to clamp the fuse fixedly in placeor to release the fuse for removal.

'7. A fuse block consisting of a pair of insulated pockets disposed in spaced relation and arranged to receive the end portions ofa fuse,

terminal support means in each pocket having an opening therein, a' terminal member in each pocket having a head for engaging the fuse end and a stem integral with the head and arranged the terminal member to a circuit, and means for urging one terminal member toward the other to clamp the fuse between the heads thereof;

8. The structure of claim 7 wherein the insuets to engage a greater area of the fuse ends and compensate for misalignment;

11. Aofuse block'consisting of a pair of insu- 'lated pockets'disposed in spaced relation and arranged to receivefthe end portions of a fuse,

a terminal support in each pocket, a sleeve extending through one terminal support, an opening in the other terminal support alignedwith the boreof the sleeve, a terminal member in each pocket having-ahead for engaging the fuse end,

an axially disposed stem integral with the head for connecting the terminal .member-toa circuit;

the stem of one terminal member extending 40 through the sleeve and the other through said f I opening, and means for moving-the sleeve axially to engage the head-and clamp the fuse between the heads of the terminal members.

12. The structure, of claim '11 wherein the to extend through said opening forconnecting V 10. The structure of claim 7 wherein the ter-- minal members may swivel relative to the pock- 

